John of Landsberg was a German prior of the Carthusian monastery in sixteenth century Cologne. In this book, he sought to make more tangible the instruction of Jesus Christ to lay people everywhere by addressing a letter to them as written by Jesus himself. In much the same way was as "The Practice of the Presence of Christ", the letter makes Jesus's words more immediate. John's theology is very characteristic of his age. It demands total love for Jesus and Jesus only. Contemplation is paramount, as is humility before God, and a focus on the interior self while treating the exterior world with detachment.